One boy was shot in the upper arm and chest; he was treated and released from Washoe Medical Center. A girl received a superficial wound to the leg from shrapnel and was treated at the scene, police said.

The alleged shooter, an eighth-grader, was arrested and police said they recovered the weapon, a .38-caliber pistol.

The youth was booked into the Washoe County Jail as an adult on a charge of attempted murder, and was being held in lieu of $150,000 bond, Donnelly said. He also was charged with use of a deadly weapon and use of a firearm by a minor.

He allegedly brought the gun to Pine Middle School with the intent of using it, but apparently fired at the two victims randomly, Donnelly said. Investigators do not know how or where he might have obtained the gun.

More than a dozen students and others witnessed the shooting outside the school cafeteria just before 9 a.m., police said.

Investigators were withholding the names of the victims -- both eighth-graders -- and the teacher who persuaded the shooter to drop the gun.

Steve Mulvenon, spokesman for the Washoe County School District, said the teacher had requested that her name not be released.

"She didn't want any publicity," he said.

Donnelly said the teacher was in a nearby room when she heard three shots fired.

"She came out into the hallway and confronted him as he was standing in the hallway holding this gun. She basically challenged him -- verbally challenged him: 'Drop the gun; put the gun down,' " Donnelly told KKOH Radio in Reno.

After the boy dropped the gun, the teacher "bear hugged" him until additional staff arrived on scene, Donnelly said.